Locks and keys



J. w. TAYLO R LOCKS AND KEYS Nair. 3, 1-970 2 Sheets-Sheet 1 Filed Jan. 25, 1968 Nov. 3; "1 970 v J. w. nY-Loiqf 3,537,284

LOCKS AND KEYS Filed Jan. 25, 1968 I Z'S hQetS-SheetB v INVENTOR hag/4L v United States Patent 3,537,284 LOCKS AND KEYS Jack William Taylor, Bournemouth, England, assignor to Ingersoll Locks Limited, London, England, a British company Filed Jan. 25, 1968, Ser. No. 700,419 Int. Cl. E05b /08, 19/02 US. Cl. 70-403 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to locks and keys of the kind including a casing and associated cover plate and a key having a circular shank having either a single bit or hit portion or two bits or hit portions, spaced key bearing holes being provided at opposite sides of the casing for supporting the key at spaced points when inserted in the casing, the bearing holes being formed in the wall of the casing and cover plate or if the casing contains a key receiving bush, in opposite ends of the bush. If security plates are provided at one or both sides of the casing then if two such security plates are used the bearing holes may be formed in the two security plates. If only one security plate is provided then one bearing hole may be formed in the security plate and the other bearing hole formed in the wall of the casing or cover plate. Hitherto the two spaced bearing holes were of the same diameter.

The term lock is broadly used and is intended to include rim and mortice locks, deadlocks, locking latches and the like in which the impediments such as pivoted or pivotless levers, tumblers, sliders, disc or sliding tumblers, pintumblers, wafers and the like are positioned within the depth of the lock casing, the depth of the easing when necessary being increased locally from one or both sides to contain the impediments, the levers or the like hereinafter referred to as impediments being moved by the inserted key to enable the locking bolt or deadbolt to be moved by the key into or out of the locked position.

Such locks may be designed for the entry of the key from one side only in which case the key will have a single bit or bit portion or may be designed for entry by the key from either side in which case the key will have two bits or bit portions as for example in the case of the lock and key forming the subject of my earlier patent application Ser. No. 685,407, now US. Pat. No. 3,486,354, one bit or bit portion engaging and operating the impediments when the key is inserted from one side of the casing, the second bit or bit portion operating the impediments when the key is inserted from the opposite side, the inoperative bit or bit portion being free to turn in an extension of the lock casing free from impediments or in a recess in the door or the like with which the lock is associated.

As previously proposed the key shank had a larger diameter collar or shoulder portion for limiting key entry into the casing and correct alignment of the notches with the impediments or in the case of the lock and key forming the subject of the earlier patent above referred to, entry of the key from opposite sides of the casing was governed by the different cross-sectional form of the key 3,537,284 Patented Nov. 3, 1970 bearing holes, the effective diameters of the key bearing holes however being the same.

Locks in which the key bearing holes on opposite sides of the casing are of circular shape and have the same diameter have security limitations because keys having the same diameter throughout the length of the shank are readily available in all sizes and consequently it is difiicult to prevent unauthorised duplication. Furthermore the difiering potential of such locks is limited to the number of diflferent combinations possible by the arrangement of the impediments within the lock casing.

The location of the key by the abutment of the collar against the outer side of the casing from which the key is first entered determines that the size of that part of the key for rotation within the lock casing shall be made to comply with the manufacturing tolerances in the depth of the lock casing and in the thickness of the material at each side and this has the efiect of limiting the use of the impediments or alternatively creates the need for a casing of greater depth or causes weakness in the steps of the key for cooperation with the impediments or i-mposes strict accuracy in the manufacturing sizes of the key.

The chief object of the present invention is to evolve a lock and key of the kind set forth of a generally improved construction, particularly from the point of view of security and which can be cheaply and easily manufactured.

In a lock and key of the kind set forth and in accordance with the present invention, the key bearing holes on opposite sides of the lock casing are of different effective diameter, the key being formed with portions of diameters corresponding with those of the key bearing holes, the key shank being formed with a boss having a diameter greater than the effective diameter of either bearing hole, which bOSs provides a shoulder which by its engagement with the casing or other fixed part limits key entry into the casing, the boss and the smaller diameter key bearing hole being so shaped as to permit the passage of the boss therethrough when the key is introduced into the casing from the side having the smaller diameter bearing hole.

Referring to the accompanying drawings:

FIGS. 1 and 2 are fragmentary sectional views showing the invention applied to a lock casing and associated key having two bits and designed for entry into either side of the lock casing;

FIGS. 3 and 4 illustrate the key in side and end elevation;

FIGS. 5 and 6 are fragmentary sectional views showing the invention applied to lock casing and associated key having a single bit;

FIG. 7 is a fragmentary sectional view showing the invention applied to a lock casing incorporating a rotatable bush for the entry of a key having two bits from either side of the lock; and

FIGS. 8 and 9 are sectional views drawn to an enlarged scale showing the cross-sectional shape of the preferred form of key and the key bearing holes in the lock casing or associated part.

Referring in the first case to FIGS. 1 to 4 in conjunction with FIGS. 8 and 9, the lock casing for convenience of description is indicated by reference numeral 1 and the cover plate by 2. The key includes a shank 3, a bow 4 and two spaced bits 5 and 6 for alternative engagement with the impediments in the lock casing according to the direction of key entry. Bits 5 and 6 are spaced apart a distance at least equal to the thickness of metal comprising the lock casing.

The key is formed with two adjacent incomplete circular section portions 7 and 8, portion 8 having a diameter greater than portion 7, both portions having a diameter greater than that of the shank 3. A shoulder 9 is formed between portions 7 and 8 the shoulder as a result of its: engagement with the inner or outer surface of the casing according to the direction of key entry ensuring that the notches in the operative bit align with the impediments in the lock casing.

In order that the key shall be adequately supported for turning movement in the wall of the casing and in the cover plate, the casing is formed with a circular hole 10 (see FIG. 8) forming a bearing for portion 7 and with a slot 11 for the passage of either key bit. Cover plate 2 is formed with an incomplete circular hole 12 (see FIG. 9) the circular hole being rendered incomplete by inwardly directed radial parts 13 providing lands, the inner ends of which form an incomplete circular bearing hole 14 for the key shank.

To allow portions 7 and 8 to pass through the cover plate into the position shown in FIG. 1, portions 7 and 8 are formed with radial slots 15 providing clearance for the projections or lands 13.

Referring now to FIGS. and, 6 which show the invention applied to a lock designed for entry by the key from one side only. The key shank as shown in FIG. 5 is shaped at its extremity similarly to portion 7 in the previously described construction and consequently similar reference numerals are used to denote similar parts. In this case, the bearing hole depicted in FIG. 9 will be formed in the wall of the lock casing 1 and that shown in FIG. 8 will be formed in the cover plate 2 although the positioning of the bearing holes may obviously be reversed.

In FIG. 6 is illustrated a slightly modified key in which the portion 7 is of increased length and again has a diameter in excess of the key shank. In this case the key shank intermediate portions 7 and 8 is reduced in diameter, the diameterof the bearing hole being correspondingly reduced. This bearing hole corresponds substantially in shape to that shown in FIG. 9 and is of smaller diameter than the bearing hole in the opposite side of the casing which receives portion 7 and is of circular form. Portion 7 is slotted radially for clearance by the radial projections and portion Sis similarly slotted merely for ease of manufacture.

In FIG. 7 is illustrated a construction wherein the lock casing incorporates a bush 16 which is rotatable with .the key the latter having two bits 5 and 6 and being insertable into the lock from either side. In this case bearing holes and 12 are formed in the bush at its extremities the central part of the bush being shaped to provide a clearance hole for the free passage of portion 8. When the key is in the position shown in FIG. 7 the shoulder 9 engages the inner surface of one end of the .bush. and when the key is inserted from the opposite side of the lock the shoulder will engage the outer opposite end of the bush to ensure alignment of the slots in the operative bit with the impediments.

4 .In allthe constructionsdescribed the diameter of the key bearing hole at one side .of the lock will be materially increased, i.e., the diameterof the hole will be in excess of the shank diameter.

I claim: 7 p 1. In an improved lock and key, the combination comprising, a lock casing including spaced walls and having means defining aligned keyways of different diameters therein, a key, said key having a shank portion and at least one bit element comprising lock actuating means thereon, at least one abutment means for cooperation with the aligned keyways in said lock casing carried by said shank portion, said abutment means provided with circumferentially spaced grooves adapted to cooperate with land means provided in at least one of the keyways of the spaced walls of the lock casing and enabling the key to be brought into a lock actuating position between the spaced walls of the lock casing with the ingress of said abutment being restricted by at least one wall of the lock casing.

2. In an improved lock and key as claimed in claim 1, wherein the aligned keyways are provided with a rotary barrel means.'

3. In an improved lock and key as claimed in claim 2, wherein the casing includes locking mechanism and the barrel includes radially extending means arranged to actuate the same. 4. In an improved lock and key as claimed in claim 1, wherein the bit elements are longitudinally spaced relative to the length of the key shank bya distance equivalent to the thickness of one wall of the lock casing.

5. In an improved lock and key as claimed in claim 1, wherein secondary abutment means are juxtaposed adjacent the said one abutment means.

6. In an improved lock and key as claimed in claim 5, wherein said second abutment means are formed with grooves complemental to the grooves provided in said one abutment means.

References Cited UNITED STATES PATENTS Thomshrin -355 306,976 10/1884 1 845,613 2/1907 Caldwell 70-129 7 962,287 6/1910 Finninger 70--150 1,074,418 9/1913 Doughty 70453 1,077,846 11/1913 Mayer 7039'3 FOREIGN PATENTS 669,637 12/1938 Germany."

MARVIN A. CHAMPION, Primary Examiner R. A. WOLFE, Assistant Examiner US. 01. X.R-. 70-409, 454 

